When grown at 20°C in MRS containing 8% ethanol, the ΔctsR::cat strain exhibited a 1.2-fold (P = 0.01)-higher growth rate than did the parental strain, whereas the ΔhrcA::cat and ΔctsR ΔhrcA::cat mutants grew similarly to wild-type cells (Fig. 6B). This indicates that CtsR negatively influences the growth rate in MRS containing ethanol at 20°C and that the growth advantage of the CtsR-deficient strain in ethanol is abolished when HrcA is absent. This result indicates an overlap in the CtsR and HrcA regulatory networks as was previously predicted (50).